This invention relates to a temperature control and drip valve assembly for a steam iron. This invention is primarily concerned with household steam irons but aspects of the invention may be useful in other applications.
Steam is created in a steam chamber of a steam iron by passing water through a drip valve onto the heated soleplate of the iron. Because different temperatures are required for satisfactory pressing of different fabrics, steam irons are provided with thermostats for adjusting the heat output of the heating element that heats the soleplate. A steam iron is incapable of producing steam at lower temperature levels and can produce increasing amounts of steam as the temperature levels increase. Because there is a correlation between the temperature of the soleplate and the amount of water which should be introduced into the steam chamber to produce steam satisfactory for ironing which is neither superheated and dry or unduly wet, steam irons are provided with mechanisms for varying the amount of water introduced into the steam chamber in accordance with the temperature settings of the heating element. These mechanisms also ensure that water will not be introduced into the steam chamber if the soleplate is insufficiently hot to produce steam. There is an ever-present need to provide improved assemblies for controlling the amount of steam produced, if any, relative to the temperature setting of the heating element.
This invention provides an improved temperature control and drip valve assembly for a steam iron.
An object of this invention is to provide an improved temperature control and drip valve assembly which provides for a positive control of the amount of water introduced into the steam chamber of a steam iron in relation to the temperature setting of the steam iron.
A temperature control in accordance with this invention includes a rotatable temperature control knob, a rotatable drive member connected to said knob for rotation therewith, and a thermostat having a rotatable temperature adjusting shaft connected to the drive member for rotation therewith. Rotation of the control knob can thereby be used to control the temperature generated by the heating element.
Further in accordance with this invention, the control knob has a vertical shaft having a downwardly-facing shoulder and the drive member has an upwardly facing shoulder confronting the downwardly-facing shoulder. The shoulders have complementary cam surfaces engaged by a cam follower which is integral with a vertically movable valve stem which has a lower end that cooperates with a valve seal to control the amount of water permitted to drip from a water reservoir into the steam chamber. Accordingly, rotary movements of the control knob to control the temperature generated by the heating element are also transmitted to vertical movements of the valve stem.
Further in accordance with this invention, a self-cleaning capability is provided for flushing the steam chamber and its steam vents by fully opening the valve port so that the steam chamber can be filled with water from the water reservoir. To this end, the control knob is vertically movable relative to said drive member through a limited distance which is sufficient to fully open the valve port, as will be described further below.
Other objects and advantages will become apparent from the following description and the drawings.